Question 2 :
A current $i$ passes through a wire of length $L$, radius $R$ and resistively $\rho$. The rate of heat generated is

Question 3 :
<span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">There is 10 units of charge at the centre of a circle of radius 10m. The work done in moving 1 unit of charge around the circle once is:</p>

Question 4 :
From below which are the applications of heating effect of electric current?<br>

Question 5 :
A bullet of mass 2 g is having a charge of 2 $\mu$ C. Through what potential&#160;difference&#160;must it be&#160;accelerated, starting from rest, to acquire a speed of 10 m/s ?&#160;&#160;

Question 6 :
A piece of copper and another of germanium are cooled from room temperature to 80K. The resistance of

Question 7 :
The resistance of a hot tungsten filament is about $10$ times the cold resistance. What will be the resistance of $100\ W,\ $ <br> $200\ V$ lamp when not in use?

Question 8 :
Assertion : Material used in the construction ofa standard resistance is constantan or manganin<br>Reason : Temperature coefficients of constantan and Magnanin arevery small<br>

Question 9 :
A thermocouple is made from copper and iron. at the hot junction, the current

Question 10 :
<span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">The two surfaces A and B are at the same potential and separated by a distance $r$. The work done in carrying a charged particle ($q$) from A to B will be:</p>

Question 11 :
Two cylindrical rod have area of cross-section$A_1$ $A_2$. If $A_1$ is greater than $A_2$. Then which of the following is correct?

Question 13 :
The potential energy of a proton is $3.2\times 10^{-18}J$ at a particular point. The electric potential at this point is:(Given charge on a proton is $1.6 \times 10^{-19}\ C$)

Question 14 :
What is the total resistance when four resistors of $20, 40, 60$, and $80$ respectively are connected in parallel (in ohm)?

Question 15 :
An electric lamp is marked $60\ W,\ 220\ V$. The cost of kilo watt hour of electricity is $Rs.\ 1.25$. The cost of using thing lamp on $220\ V$ for $8\ hrs$ is:

Question 16 :
As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity<br>

Question 17 :
<span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">A point positive charge of Q' unit is moved round another positive charge of Q unit on a circular path. If the radius of the circle is r, the work done on the charge Q' in making one complete revolution is:</p>

Question 18 :
Assertion : The resistance of a milliammeter isgreater than that of ammeter<br>Reason : Shunt resistance in case of amilliammeter is more than that of ammeter<br>

Question 20 :
The smallest resistance that can be obtained by combining 10 resistors each of resistance $10 \Omega$is